This magical-seeming garment will radiate a dim aura of Enchantment if magic is detected for. 

The wearer will notice nothing unusual when the robe is donned, and it will actually convey some magic power at that time—protection +1, for example. However, as soon as the wearer is in a situation which requires his or her concentration and action against hostile opponents, the true nature of the garment will be revealed. 

The wearer will immediately suffer a multitude of bites from the vermin which will magically infest the garment. He or she will have to cease all other activities in order to scratch, shift the robe, and generally evidence all signs of extreme discomfort from the movement and biting of these pests. Thus, the wearer is unable to gain initiative, and he or she will certainly have a 50% chance of actually being unable to complete a spell due to the vermin. All other actions and attack forms requiring manual/locomotive/somatic activity are at only one-half normal probability.

The dweomer of the garment prevents its removal except by means of a remove curse spell or similar magic.